iOS 4.1 beta for iPhone 4, 3GS, 3G, and iPod Touch 3G, 2G build 8b5080c along with SDK 4.1 beta is now available for download to developers only. If you’re a registered Apple developer you can download iOS 4.1 beta from the iPhone Dev Center.

What’s New in iOS 4.1 Beta Firmware

The new signal bars appear slightly taller than the previous ones, and presumably Apple’s calculations regarding signal strength has been revised.

The modem firmware goes 02.07.01 from 01.59.00.

WARNING: Avoid the iOS 4.1 beta firmware if you depend on unlock as it comes with a baseband update. Jailbreakers should also avoid it until further notice.

Many users have been waiting for a promised iOS software update to address reception issues on the iPhone 4. Early reports indicates that there’s no improvement.

Download iOS 4.1 Beta 8b5080c

iOS 4.1 beta is available to developers only. Developers can download iOS 4.1 from the iPhone Dev Center. However, if you still want to give it a shot, Google the queries listed below. (Please don’t ask for the links)

Download iOS 4.1 for iPhone 4

iPhone3,1_4.1_8b5080c_Restore.ipsw

ios_4.1_beta__iphone_4__8b5080c.dmg

Download iOS 4.1 for iPhone 3GS

iPhone2,1_4.1_8b5080c_Restore.ipsw

ios_4.1_beta__iphone_3gs__8b5080c.dmg

Download iOS 4.1 for iPhone 3G

iPhone1,2_4.1_8b5080c_Restore.ipsw

ios_4.1_beta__iphone_3g__8b5080c.dmg

Download iOS 4.1 for iPod Touch 3G

iPod3,1_4.1_8b5080c_Restore.ipsw

ios_4.1_beta__ipod_touch__3rd_generation__8b5080c.dmg

Download iOS 4.1 for iPod Touch 2G

iPod2,1_4.1_8b5080c_Restore.ipsw

ios_4.1_beta__ipod_touch__2nd_generation__8b5080c.dmg

If you’re still running iOS 4, you can jailbreak iPhone 3GS, 3G, iPod Touch 3G, 2G using the guides linked below. Unlock guide for iOS 4 are also linked.